This application claims the benefit of Korean Patent Application No. P2000-83095, filed on Dec. 27, 2000, the entirety of which is hereby incorporated by reference for all purposes as if fully set forth herein.
1. Field of the Invention
The present invention relates to a displaying apparatus, and more particularly to a liquid crystal display and driving method thereof.
2. Background of the Related Art
Generally, a liquid crystal display (LCD) includes a thin film transistor (TFT) liquid crystal display (TFT-LCD) panel, a backlight unit, and a driver. The TFT-LCD panel may have degradations as follows: first, degradation of characteristic values from standard design due to process deviations; second, degradation due to dust, poor cleaning at a film surface, and the like; and, third, degradation of characteristic variations due to static electricity and breakdown of thin film transistors or liquid crystal cells.
One of the degradations occurring in a TFT-LCD panel is the irregularity of combining a first substrate with an opposed second substrate, which results in reducing the sharpness of a displayed video or in leaking light when failing to meet the design margin.
Reference will now be made in detail to an LCD according to a related art, examples of which are illustrated in the accompanying drawings.
FIG. 1 shows a layout of an LCD according to a related art.
Referring to FIG. 1, a liquid crystal display generally comprises a number of xe2x80x98mxe2x80x99 gate lines G1 to Gm arranged in a first direction with a constant interval between the gate lines; a number of xe2x80x98nxe2x80x99 data lines D1 to Dn arranged in a second direction perpendicular to the respective gate lines G1 to Gm with a constant interval between the data lines; a plurality of pixel electrodes (not shown in the drawing) formed as a matrix in pixel areas defined by the crossing gate and data lines respectively; and a plurality of thin film transistors for applying data signals supplied through the respective data lines to the respective pixel electrodes by being switched according to signals of the gate lines.
Further, a pair of driver integrated circuits (ICs) 14 and 15 are installed at the sides of the gate and data lines, respectively, so as to supply gate and data driving signals thereto. Namely, a pair of pads (not shown in the drawing) are formed at the ends of the gate and data lines to which the driver ICs are connected.
FIG. 2 shows cross-sectional views of the LCD taken along a line I-Ixe2x80x2 in FIG. 1.
Referring to FIG. 2, a gate insulating layer 22 is formed on a first substrate 21. An nth data line 23 is patterned on the gate insulating layer 22. A passivation layer 24 made of an insulator is formed over an entire surface of the substrate including the nth data line 23. A transparent conductive layer of indium tin oxide (ITO) 25 for applying a voltage to the liquid crystal display is patterned on the passivation layer 24.
A black matrix 27 having predetermined spaces therein, is formed on an upper insulating substrate 26. A color filter layer 28 fills the spaces in the black matrix 27.
Unfortunately, the LCD according to the related art has some problems as follows.
The degree of alignment for the TFT and color filter substrates depends on the alignment tolerance (or margin) for combining (or assembling) the upper and lower substrates. Such combining margin is determined by the design of the respective substrates, for which precision of about several micrometers is required. Light leakage occurs at both lateral sides of the panel when the alignment between two substrates is deviated from the combining margin, thereby failing to provide desirable driving characteristics.
Namely, as shown in FIG. 2, there is no structure to block the light leakage at the right side of the nth data line 23. Therefore, light leakage occurs due to the transmitting light reaching the color filter layer.
Accordingly, the present invention is directed to a liquid crystal display and driving method thereof that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An advantage of the present invention is to provide the provision of a liquid crystal display and driving method thereof, in which additional dummy gate and data lines are formed to prevent light leakage at both lateral sides of the panel due to the combining irregularity of the panels.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages, and in accordance with the purpose of the present invention as embodied and broadly described, a liquid crystal display according to the present invention includes m valid gate lines G1 to Gm arranged in a first direction with first constant intervals between the valid gate lines; n valid data lines arranged in a second direction perpendicular to the valid gate lines with second constant intervals between the valid data lines; and at least one dummy data line at a periphery of and in parallel with the n valid data lines.
In another aspect of the present invention, a liquid crystal display according to the present invention includes m valid gate lines G1 to Gm arranged in a first direction with first constant intervals between the valid gate lines; n valid data lines arranged in a second direction perpendicular to the valid gate lines with second constant intervals between the valid data lines; a dummy gate line in parallel with the valid gate lines at a periphery of the m valid gate lines; and at least a first and a second dummy data line at left and right sides of the n valid data lines.
In a further aspect of the present invention, a liquid crystal display in a TFT-LCD panel includes a first substrate on which a black matrix layer and a color filter layer are stacked sequentially on a first insulating substrate; a second substrate on which a gate electrode, a gate insulating layer, an active semiconductor layer, source and drain electrodes, and a passivation layer are stacked on a second insulating substrate, wherein the second substrate opposes the first substrate; and a liquid crystal layer between the first and second substrates, wherein the passivation layer is formed of an organic insulating material.
In another further aspect of the present invention, a method of driving a liquid crystal display including a valid data line area in which a plurality of data lines D1 to Dn are formed; areas of a first dummy data line and a second dummy data line formed at left and right sides of the valid data line area; a valid gate line area in which a plurality of gate lines G1 to Gm are formed; and a first dummy gate line formed at one side of the valid gate line area, includes applying a first same driving signal to the first dummy data line and a second data line D2 in a plurality of the data lines and a second same driving signal to the second dummy data line and (nxe2x88x921)th data line Dnxe2x88x921, and applying a pulse waveform synchronized to a waveform applied to the mth gate line Gm to the dummy data lines.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.